This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. To ascertain a minimum of 420 pedigrees from 7 sites (Harvard University, the Mount Sinai School of Medicine, UCLA, UCSD, UCHSC, the University of Pennsylvania, and the University of Washington) and 5 years of the project with a proband who has schizopherenia, by DSM-IV criteria. There must always be at least one parent and one other sibling in the pedigree (although the projected average pedigree size will be 4). To obtain the following robust and quality assured phenotype measures in this sample, in addition to a structures (DIGS) diagnosi: P50 suppression, prepulse inhibition of acoustic startle, antisaccade, continuous performance test, verbal memory, and working memory. To perform complex segregation analyses to determine which of these variables (a) are likely to reflect the same underlying neuronal processes, and (b) indicate genetic transmission of risk for schizophrenia. To perform a genome scan with polymorphic markers to assess the presence of genetic linkage of phenotypes identified in specific Aim 3 to specific chromosomal loci. Based on the data from specific aim 4, to model the neurobiological basis of risk for schizophrenia, as a combination of specific elements of genetically or non-genetically determined brain dysfunction.